Relay having improved construction



April l, 1969 G. E. PERREAULT 3,436,693

v RELAY HAVING IMPROVED CONSTRUCTION me@ March so, 1967 a0 L/A F /G /4 33 33 33 FIG 3 33 HV1/avm;

BVG. E. PE RREAUL A TTOR/VEV United States Patent O 3,436,698 RELAY HAVING IMPRGVED CONSTRUCTION George E. Perreault, White Plains, N.Y., assignor to Bell Telephone Laboratories, Incorporated, Murray Hill, NJ., a corporation of New York Filed Mar. 30, 1967, Ser. No. 627,199 Int. Cl. H01h 1/66 U.S. Cl. 335--154 8 Claims ABSTRACT F THE DISCLOSURE A relay comprising a relay switching assembly, a magnetic cover and magnetic return path members. The relay switching assembly uses a coil and sealed contacts and is capable of independent operation. The return path members magnetically couple the operative elements in the relay while performing mechanical functions.

BACKGROUND `01:" THE INVENTION Field of the invention This invention relates to sealed contact relays and especially to those in which the supporting component is a bobbin.

Description of the prior art SUMMARY OF THE INVENTION According to a preferred embodiment of this invention, a sealed contact relay comprises a switching element, a coil, a plurality of terminals, a support, .a magnetic cover and a plurality of magnetic return path members. The support is a hollow bobbin having an L-shaped ilange at each end and a winding section in the middle. The coil is wound on the winding section, the terminals are mounted in the L-shaped flanges, and the switching element is disposed in the hollow of the bobbin and supported by the terminals.

The magnetic cover fits over the bobbin and the return path members bracket the L-shaped flanges and have two legs joined by a U-shaped end section. The U-shaped end section provides mounting space for selected terminals, while the legs are positioned adjacent the coil and switch element, respectively, to increase the magnetic coupling between the two.

BRIEF DESCRIPTION OF THE DRAWING FIG. l is an elevation view of an embodiment of this invention with parts broken away to show interior details;

FIG. 2 is an elevation view of the interior of the embodiment shown in FIG. l with selected portions broken away to show detail;

FIG. 3 is a plan view of the embodiment shown in FIG. 1 with selected parts broken away and selected parts shown in phantom to illustrate detail;

FIG. 4 is an end section taken along the line 4-4 of the embodiment shown in FIG. 2;

FIG. 5 is a perspective view of a return path member.

DETAILED DESCRIPTION A relay embodying this invention is illustrated in 3,436,698 Patented Apr. 1, 1969 Yl C@ FIG. l. The relay 10 comprises three basic elements, viz., a relay switch assembly 11, a cover 30 and a plurality of return path members 31.

The relay switch assembly 11 is a subassembly which comprises a support 12, terminals 13, a coil 14, and a switch element 15. The relay switch assembly 11 is the operative part of the relay 10 and can even function effectively by itself. As a help in understanding the nature of the relay switch assembly 11, each of its components is separately described below in detail.

The support 12, as illustrated in FIG. 2, is a bobbin comprising two end flanges 16 and a central portion 17. The central portion 17 extends between the two end flanges 16 and is hollow so as to form a tunnel through the entire support 12. The end flanges 16 each have a platform portion 18. Each platform portion 18, as illustrated in FIG. 4 has one or more apertures 19. The bobbin structure is conveniently made of nylon.

The central portion 17 functions as a winding base for the coil 14. The coil 14 supplies the magnetic ux which operates the relay 10. It terminates on selected terminals 13, and the end flanges 16 are slotted, as shown in FIGS. 3 and 4, so as to facilitate the passage of the coil ends from the -winding portion to the terminals 13.

The terminals 13 are made of an electrically conducting material such as brass. They divide naturally into upper and lower portions. As can be seen in FIG. 4, each lower portion fits into an aperture 19 while each upper portion serves generally as an electrical connecting point.

The upper portion of each terminal 13 includes a projection, or tab, 20. In one case, the projection 20 extends generally parallel to the platform portion 18, while in another, it extends generally perpendicular to the platform portion 18. In both cases, however, the projections 20 facilitate electrical connections. In the former, viz., the central terminals 13" best seen in FIGS. 3 and 4, the projections 20 also provide a positioning support for the switch element 15. In fact, the switching element 15 is entirely supported and positioned between opposite terminals 13' and within the support 12 by two of the projections 20.

In the embodiment illustrated herein, the upper portions of the terminals 13 extend either straight up from the surface of the platform portion 18 or are bent at about a 45 degree angle. The bend simplifies manufacture and the angle can be adjusted from 45 degrees to any other angle required by changing circumstances.

The switching element i15 is the last component of the relay switch assembly 11. As illustrated in FIG. 2, it contains a single conventional reed switch. It need not, however, be restricted to only one switch; two or more switches can readily be used. Moreover, the switches themselves can be of `diferent types, viz, reed switches or mercury switches.

The components just described, when joined together, form the relay switch assembly 11. To complete the relay 10 the relay switch assembly 11 is combined with the magnetic cover 30 and the magnetic return path members 31.

The cover 30 functions principally to provide physical protection. It is made of a magnetic material, however, and cooperates with the magnetic return path members 31 to improve the use of available magnetic llux. In the embodiment illustrated herein, the cover is made of a low reluctance magnetic material such as annealed cold-rolled steel.

The magnetic return path members 31 are made of annealed Permalloy and have 4a low magnetic reductance. Their principal function is to improve the magnetic coupling between the coil 14 and the switch element 15.

As shown in FIG. 5, each of the magnetic return path members 31 comprises a U-shaped end section 32 and two parallel legs 33 and 33 joined to the end section 32 by a pair of shoulders 34. When positioned on the support 12, the legs 33 and 33 bracket portions of an end ange 16 and the central portion 17. As shown in FIG. 4, the periphery of the end flange 16 includes a pair of notches 35. One shoulder 34 on each magnetic return path member 31 engages a notch 35 when in place.

Similarly, each end flange 16 includes a pair of notches 36 disposed adjacent to the opening leading into the hollow part of the central portion 17. The notches 36 are illustrated in FIG. 4 and are adapted to engage the remaining shoulder 34 on the magnetic return path member 31. When the shoulders 34 are engaged by the notches 35 and 36, the magnetic return path member 31 is held in position with respect to the support 12.

As shown in FIG. 3, when the magnetic return path member 31 is in place, the =Ushaped end section 32 is disposed around one of the terminals 13. As a result, the terminal 13 has increased protection from physical injury.

The two legs 33 and 33' on each magnetic return path member 31 are of different lengths. When installed, as shown in FIG. 3, the two outer legs 33 of opposite magnetic return path members 31 practically abut while the inner legs 33 have a space between their ends. The inner spacing forces flux from the coil 14 to concentrate in the contacts of the switching element 15.

The shape of each magnetic return path member 31 helps to improve flux usage. Specifically, the shorter leg 33 as shown in FIG. 5 has a curvature adapted to lit the curved side of the switching element 15. The close iit between the two saves spaces and improves the magnetic coupling between the leg 33 and the switching element 15. The remaining leg 33 is at so as to lie along the magnetic cover 30. As the magnetic cover 30 has a low magnetic reluctance, coupling is improved between the magnetic cover 30 and the coil 14. Finally, as shown in FIGS. 1 and 2, the end section 32 is positioned so as to abut the magnetic cover 30. As a result, still more of the magnetic return path member 31 is in contact with the magnetic cover 30 thereby further improving magnetic coupling. Thus, the magnetic coupling between the elements in the operative magnetic circuit of the relay is improved.

When the relay 10 is operated, the coil 14 induces a magnetic flux. The magnetic flux surrounds the coil 14 and passes through the central portion 17 of the bobbin. The cover 30 and the legs 33 of the return path members 31 form a preferred path around the coil 14 while the legs 33 direct the flux in the central portion 17 of the bobbin into a specific part of the switching element 15. As a result, the available flux is concentrated in the operative portions of the relay 10.

Test results comparing the operating characteristics of relays show that the magnetic return path members 31 increase the sensitivity of the relay by a factor of two to one.

Finally, the relay 10 is particularly suited for use with printed circuit boards. The terminals 13 mounted opposite each other in opposite end iianges 16, for example, are aligned with each other. Similarly, the spacings between the terminals 13 in the same end flange 16 are all equal. Thus, when the relay 10 is assembled, it can readily be arranged to fit the integral mounting multiples found in standard printed circuit boards.

In summary, a relay has been disclosed herein which exhibits markedly improved characteristics. While only one embodiment has been disclosed, it is to be understood that it is merely illustrative of the principles of this invention and tho-se skilled in the art will readily be able to construct other embodiments which fall within the scope of the invention.

What is claimed is:

1. In a switching device, the combination comprising:

a relay switch assembly including a hollow support, a

Switching element mounted in the hollow of said support, terminals mounted at the ends of said support, and a coil wound around the middle of said support;

a skirted cover mounted on said support to encapsulate said switching element, terminals and coil; and

metallic return path members for concentrating magnetic ilux from said coil in said switching unit, each of said return path members being attached to said relay switch assembly and having an end section extending from one end of said support and pressing against the skirt of said cover whereby the magnetic coupling between said cover and said coil is improved and spaces are provided at the ends of said support for the mounting of terminals.

2. The combination in accordance with claim 1 wherein each return path member includes two parallel legs, a U-shaped end section and two shoulders for joining said legs to said U-shaped end section and for positioning said return path on said support.

3. The combination in accordance with claim 1 wherein said return path members include two legs, one of said legs being positioned adjacent said switch unit and being curved to follow the contour of said switch unit whereby the eliciency of flux usage is improved.

4. The combination in accordance with claim 1 wherein said support has a flange at each end.

5. The combination in accordance with claim 4 Wherein each ange includes a platform portion for mounting'l said terminals.

6, In a switching device the combination comprising:

a support adapted to accept a magnetic cover and having two L-shaped flanges separated by a hollow winding portion;

a plurality of terminals projecting from said L-shaped flanges;

a magnetic iiux generating coil wound on said winding portion and connected to at least two of said terminals;

a switching unit operatively responsive to magnetic iiux from said coil, said switching unit being disposed in the hollow of said winding portion and supported at each end by a leadout element resting on one of said terminals; and

a plurality of return path members wherein each return path member lbrackets a portion of said support and is adapted to concentrate magnetic flux from said coil in said switching unit, said return path members each including two parallel legs disposed along opposite sides of said winding portion, an end section, and two shoulders for joining said legs to said end section and for positioning the return path member on a flange, each end section adapted to iit around one or more terminals on said flanges and to be positioned by the cover when placed on said support.

7. The combination in accordance with claim 6 wherein said end section is U-shaped.

8. In a relay, the combination comprising:

a support having two ends with a flange on each end and a tunnel extending continuously through said support from end to end, each of said flanges having a platform portion with at least one aperture therein;

a control coil wound on said support structure between said flanges;

terminals mounted in said apertures in said platforms with an upper portion and a lower portion of each terminal extending, respectively, above and below said platform portion, each of said upper portions having a projection thereon extending parallel to said platform portion;

a switching element having leadout elements extending from each end thereof, said switching element being suspended within said tunnel between a pair of positioned terminals with said leadout elements mounted on the projections on said terminals; and

return path members attached to said support, each of said return path members having a low magnetic reluctance and including two parallel legs joined by a U-shaped end section, each of said legs being disposed inside of said tunnel adjacent to said switching element and said end section |being disposed around one of said terminals.

References Cited UNITED STATES PATENTS 3,002,066 9/1961 Ketchledge et a1. 335-151 X 10 6 3,167,625 1/1965 Russo 335-154 3,268,839 8/1966 McFarland 335-202 3,302,143 1/1967 Harkenrider 335-154 BERNARD A. GILHEANY, Primary Examiner. R. N. ENVALL, JR., Assistant Examiner.

U.S. C1. X.R. 335-202 

